Air-pump.



A. M. KJAERSGAARD & C. S. J. WIBSB.

AIR PUMP.

APPLIGATION run 1130.1, 1908.

Patented Aug. 24. 1909.

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Inventors. Z t m wltnesses. 92m 1 $142: W4

AUGUST MAB-1U! KIAERS jAii-gPnmps, of which the oith'e'kind in which a UNITED s'ratr nsr rnur OFFICE.

GAABD, OF COPENHAGEN, AND CARL SOEB-EN JULIUS WIESE. 0F ODENSE,

DENMARK.

AIR-PUMP.

Specification of Letters Patent.

Application-filed December 1, 1908. Serial No. 466,490.

To all whom wit may concern);,

Be it known that we, AUGUST MARIUS Kunnsonnno; manufacturer, and Calm Sonnmv JULIUS Wmsn, managing director, citizens of Denmark, residing at No. 28 Frederikssundsvej, Co enhagen, and'No. 18 Vestergade, Odense,' enlnark, respectively, have lnvented new and useful Imfprovements in 1 ollowing is a specification.

The present invention relates tMir-pumps v fluid such" as oil or the like is used for filling the empty; spaces below and above the piston whenever the latter reaches its extreme positions, the fluid being led together with the air through the valves of the pump. In these pumps a thorough mixing of the air and the oil takes place and a quantity of air-bubbles will be ormed in the oil which with the fluid are forced from the pressure-side of the piston tothe suction-side, where the compressed airbubbles will expand and extensively counter act the vacuum, so that .avacuum cannot be brought down below a certain relatively high degree. A further deficiency is due to the fact that the pores in the pumpeylinder often open without any plausible reason, and

' further that small leakage will appear inthe through leaks or packing and connections due to the influence of alterations in temperature, so that a pump may work all right one day, while the next day it can produce but a very insuflio ient vacuum. The object of the present invention is to obviate the above mentioned drawbacks by assing the fluid mixed with air, before it is ed to the suction-side of the pistomthrough a filter where the air-bubbles are separated from the liquid. The whole pump-cylinder besides the packing and connections are sura way that only a very small quantity of fluid may pass open pores while any in jurious entrance of air is avoided.

The invention is illustrated in the accom panying drawings in which- Figure 1 is a vertical section ofan air pump specially adapted for freezing-machines. Fig. 2 is a section on the line A-B of Fig. 1, and Fig. 3 is a vertical section of the lower part of another form of construction. V

a designates a pump-cylinder which communicates through 'an opening 6 with the chamber from which the air is to be exhausted. The cylinder a is closed by means of a se urate bottom a and a slightl conical cover 0 formed in one piece with the walls. A piston is reciprocally mounted in the c linder a and comprises a to -plate f an a bottom-plate g, The top-p ate is provided with openings it while the bottom-plate has a valve 70 that opens into the interior hollow space of the piston. The is'ton' is fixed to a piston-rod 'm that passest rough an annular valve 11, in the cover cl, and into a crank chamber p.

The cylinder a is surrounded by a jacket 18 which in communication atthe top with the crank-chamber p. In said chamber 7) is arranged a bracket g which serves as a guide for the piston-rod m and as an abutment for a spring 0' which surrounds the iston rotl and tends to close the valve n. aid piston rod is connected by means of a rod 8 to the crank t of a driving. shaft it, which may be driven by any suitable means, such as a crank 1 fixed on one end. The bearings c of this shaft are in the chamber 39 and may. as shown on the drawing, be ball-bearings. At the other end of the shaft u is a toothed wheel w gearing with a smaller toothed wheel 11 that is connected with a flywheel The chamber 7; is closed on top by a cover 1 in which are openings *2.

In the wall of the pump-cylinder a is formed a channel 3, which connects the interior of the chamber 1) with the cylinder at and has its outlet in the latter immediately above the piston, when the latter is in its lowest position. The other end of the channel has its opening or port at the bottom of the chamber 7) and said port is controlled b a valve 4'. The valve has a rod 5 whic asses through and is guided at oneend by the bracket and at. its other end is connected to a yoke 6 which is aided in suitable bearings 7 and surroun s the shaft u. The valve is raised at each revolution of the shaft by means of a cam 8 on the shaftenaging a cam 9 on the interior of the yoke. lhe valve is returned to its seat by the action of a spring 10 which surrounds the rod 5 and abuts against the bracket 4 and a collar 5 on the rod.

The filter is mounted on and secured to Patented Aug. 24, 1909.

the cover cl of the cylinder over the inlet end of the passage 3 and comprises a casing having concentric perforated walls 11 forming a central chamber and an annular chamber which latter is filled with felt or othersuitable filtering material. Both chambers are closed at the top by acover 11 made interal with the walls and the valve 4 passes t rough said cover which is made to form a fluid tight connection.

When the pump is in operation, the jacket 18 and the crank chamber 1 are filled with a fluid, such as oil, to about the point reached by the crank t at its down stroke. As soon as the piston in the cylinder moves upward, from the position shown in Fig. 1, the air in the cylinder above the piston will be compressed and the air to ether with the oil will be forced through the port controlled by valve n. At the same timeair will be sucked in under the piston through the hole b and when the valve 4'is raised, oil will enter the channel 3, which oil has, before reachin the channel passed through the filter 11 an all of the air-bubbles have been removed therefrom.

When the piston moves down, the oil closes the opening I) and the air below the piston passes with the oil through the valve a and through the holes h of the piston. As soon as the iston reaches its lowest position, the oil will completely fill the space ,below the iston.

T e cross-section of the channel 3 can be re lated by means of a screw 12.

the form of construction shown in Fig. 3 the channel 3 is formed'in the piston-rod m, which is surrounded above by a sleeve 18 fastened to the cover at. This sleeve also carries a filter 11". The top opening 15 of the channel 3' is just opposite a hole 14 in the sleeve 13 when the plston has reached its highest position. The channel 3 can in this position be filled with oil that has passed through the filter. When the opening 15 is just op osite the hole 14, the bottom 0 ening 16 of t e channel 3" will be closed y the sleeve 13, so that the air on to of the piston cannot pass out through the c annel 3.

When the piston travels downward, the hole 16 will be opened, and the oil will be sucked into the cylinder a.

On the bottom of the filter 11 is formed a flange 17 which prevents the air that passes. out through the valve n from influencing the passage of the oil to the filter.

We claim:

1. An air-pump com risin a cylinder provided with an air-inl eit, a fluid chamber communicating with the cylinder, means to convey fluid from the chamber to the cylinder, means to filter said fluid and means to discharge fluid and air from the cylinder into the chamber.

2. An air-pump comprising a cylinder provided with an air-inlet, a piston in the cylinder, a fluid chamber communicating with the cylinder through a port, a valve normally closing the latter adapted to be actuated by pressure in the cylinder, at fluid conduit connecting the casin and cylinder, and means to filter the fluid efore it enters the cylinder.

3. An air-pump com rising a cylinder provided with an air-in et, a pistonin the cylinder, a fluid chamber extending above the cylinder and communicating therewith through a port, a valve normally closin said port 0 ening into the chamber an ada ted to e opened during the pressure stro e of the piston, a fluid conduit connecting the chamber and cylinder, and a filter in the chamber covering the inlet end of the conduit.

4. An air-pump comprisin a cylinder provided with an air-inlet, a uid chamber' valve closing said port, a piston in the cylinder having its rod extending through the valve, a fluid conduit connecting the chamber and cylinder and having its discharge end opening into the latter near the bottom thereof, and a filter in the chamber surrounding the inlet to the conduit.

5. An 'ai ump comprisin a cylinder provided an air-inlet, a uid chamber surrounding the cylinder and extending above the same, a va 'ed port connecting the cylinder and chamber, a fluid conduit connecting said cylinder and chamber, a filter in the latter mounted over the inlet to the the conduit, 11. valve to close the latter, means to discharge the air and fluid from the cylinder into the chamber and means to open the conduit during said discharge.

extending above the cylinder and communieating therewith through a port, an annular;

6. An air-pump com rising a cylinder provided with an air-in et near its bottom and an outlet in the to a fluid chamber surrounding the cylin er and extending above the same, an annular valve opening into the chamber controlling the outlet, :1 piston in the cylinder having a rod extendin through said valve, a crank shaft journa ed in t e chamber connected. to said rod, a fluid conduit connecting the casing and a valve to close the conduit connected with the crank shaft.

7. In an aim-pump, the combination with a cylinder having inlet and discharge. ports, an a fluid chamber communicating with the cylinder through the discharge ort, of a fluid conduit connecting the chain er and c linder, and a filter interposed between the chamber and conduit.

8. In an air-pump, the combination with a c linder having inlet and discharge ports, and a fluid chamber communicating with the cylinder through the discharge ort, of names to this specification in the presence of a COIldlit eon-nesting the1 churn er and two subscribing witnesses. cy in er, an a casing mounte in the cham- I her comprising concentric perforated plates :X having a filtering medium between them so R J and forming a central andnnnnlar chamber \Vitnesses: surrounding the inlet to the oonduit. P. HOFMAN BABY,

In testimony whereof we have signed our ERNEST BOUTABD. 

